Airway anatomy

Airway anatomy
Dr Ramprasad Gorai

1. AIRWAY ANATOMY & ITS IMPLICATION IN ANAESTHESIA Dr Ramprasad Gorai PGT-Dept of Anaesthesiology R.G.Kar Medical College,Kolkata

2. AIRWAY ANATOMY UPPER AIRWAY ( Part above cricoid cartilage ) 1. Nose & Paranasal sinuses 2. Oral cavity 3. Pharynx 4. Larynx LOWER AIRWAY 1. Trachea 2. Lt & Rt Principal Bronchi 3. Secondary (Lobar) bronchi 4. Segmental (Tertiary) bronchi 5. Terminal bronchiole 6. Respiratory bronchiole 7. Alveolar duct & Sacs

3. NOSE INTERNAL NOSE 1. Lt & Rt Nasal Cavities 2. Nasal Septum Collumeller Septum Membranous Septum Septum Proper a. Cartilage 1/3 b. Bone 2/3 NASAL CAVITITY 1. Vestibule 2. Respiratory Segment 3. Olfactory Segment EXTERNAL NOSE 1. Osteo - Cartilagenous 2. Ala Nasi 3. Nasal Skin

4. 1 .Vestibule Strat column epithelium. Vestibular hair (Vibrissae) filter large particulate matter. Lamina propria a. Hair follicle b. Ecrine gland c. Sebaceous gland 2. Respiratory Segment Ciliated Pseudo strat Column Contains Goblet,Basal,Brush , Neuro -endocrine cell 3. Olfactory Segment Olfactory epithelium Contains: Bipolar neurosensory cell supporting cell regenerative basal cells

5. NASAL SEPTUM Consist of- 1. Septal Cartilage 2. Perpendicular plate( Ethmoid ) 3. Vomer 4. Crest of Nasal bone 5. Nasal Spine of Frontal bone 6. Rostrum of sphenoid bone 7. Crest of Palatine bone 8. Crest & Ant nasal spine of Maxilla

6. PARANASAL SINUS Blind ended air containing Cavity in certain skull bones. 2 groups— Anterior Group 1. Maxillary 2. Frontal 3. Ant Ethmoidal Posterior Group 1. Posterior Etmoidal 2. Sphenoid Functions 1.Warm & Humidify Inspired Air 2.Resonance to Voice

7. PHARYNX Musculo -membranous tube extend from base of skull to 6 th Cerveical Vertebra. Length -12-14 cm Width - Max 3.5 cm( Naso Pharynx) - Min 1.5 cm( Pharyngo esophageal Jn ) * 3 Part- --- 1. Naso / Epi -Pharynx 2. Oro/ Meso -Pharynx 3. Laryngo /Hypo-Pharynx At the base of tongue EPIGLOTTIS functionally separate Oropharynx from Laryngopharynx .

8. LARYNX LARYNX Lies- in front of hypopharynx & opposite to 3 rd to 6 th Cerveical vertebra. Composition- 1. CARTILAGE -3 Unpaired & 3 Paired(Total 9) UNPAIRED —Thyroid, Cricoid , Epiglottis PAIRED --- Aretenoid , Corniculate , Cuneiform 2 .MUSCLES - --Intrinsic & Extrinsic. 3. JOINTS —Cricothyroid & Cricoarytenoid 4. MEMBRANE - Intrinsic & Extrinsic 5. CAVITY - Inlet. Vestibule. Sinus of Lrynx . Infraglottic part. 6. MUCOSA -Ciliated Pseudostratified Columnar except VC-- Strat squamnous .

9. LARYNX

10. SENSORY NERVE SUPPLY NASAL CAVITY ANT -Anterior ethmoidal N ( br of Ophthalmic div-V1) POST - Sphenopalatine ( br of Maxillary div -V2) TONGUE (GEN SENSATION) ANT 2/3 —Lingual Nerve ( br of Mandibular div of Trigeminal) POST 1/3 - Glossopharyngeal nerve. PHARYNX Glossophayngeal nerve also innervate - Roof of pharynx Tonsil under surface of soft palate. LARYNX Below the epiglottis -- VAGUS . Above vocal cord - Internal Laryngeal branch Below vocal cord - Recurrent laryngeal branch

11. NERVE SUPPLY

12. TRACHEA Membrano cartilaginous tube Lower border(Carina) T4 vertebra- supine & cadaver T6 vertebra- standing & living Length - 10-11 cm Breadth -12 mm in adult. ( int diameter) 3 mm (newborn – upto 3 yr) increase by 1mm/year till 12 yr of age. Structure -16-20 C-shaped hyaline cartilage connected by strong fibroelastic memb & posterior deficit part contain involuntary trachealis muscle Relation -Thyroid Isthmus-2 nd .3 rd .4 th Ring

13. ZONE OF AIRWAY (23 generation) Conducting zone-(First 14 gen) Trachea Principal Bronchi Segmental bronchi- upto Terminal bronchiole Transitional zone-(15 th gen) Terminal bronchiole(3-4 generation) Respiratory zone-(Last 8 gen) Respiratory bronchiole Alveolar ducts Alveolar sacs.

14. BRONCHO-PULMONARY SEGMENT Def- The portion of the lungs aerated by each tertiary or segmental bronchus. Features- - an independent respiratory district. - covered by inter-segmental septa through which br of pulmonary vein runs. - the largest sub-divisions of the lobe and is surgically resectable . - supplied independently by segmental brochus and a tertiary branch of pulmonary artery.

15. Bronchopulmonary segments Right Lung : Superior Lobe : Apical Posterior Anterior Middle Lobe : Lateral Medial Inferior Lobe : Superior Anterior basal Posterior basal Medial basal Lateral Left Lung : Superior Lobe : Apico-posterior Anterior Lingular Lobe : Superior Inferior Inferior Lobe : Superior Anterior basal Posterior basal Lateral

16. Left main bronchus and its divisions

17. Rt Bronchous RIGHT BRONCHUS IS WIDER ,SHORTER AND MORE VERTICAL THAN LEFT BRONCHUS IT IS WIDER B/C IT SUPPLIES MORE VOLUMINOUS RT LUNG IT IS MORE VERTICAL B/C AT ITS BIFURCATION TRACHEA DEVIATES MORE TO THE RT SIDE

18. Right main bronchus and its divisions

19. At a glance…

20. ACINUS V/S TERMINAL RESPIRATORY UNIT ACINUS -The ultimate lung unit from each terminal bronchiole . TRU -all alveolar duct & their accompanying alveoli,that stem from the most proximal (first) respiratory bronchiole . 1 Acinus contain 10-12 TRU. Anatomist & Pathologist – Acinus . Physiologist & Pulmonologist -TRU.

21. ANATOMICAL VARIATION & IMPLICATION IN ANAESTHESIA Conventional Laryngoscopy – done in -supine position -a slight Neck flexion of 25-35 deg -Head extension of 85deg at atlanto -occipital joint to align oral,pharyngeal & Laryngeal axes. In adult a head elevation of 10 cm with a pillow is appropriate for neck flexion. No such elevation required in pediatric age gr (<8yr age) d/t their large head size. This position is called OPTIMAL SNIFFING POSITION .

22. AIRWAY ASSESSMENT • Mouth opening : an incisor distance of 3 cm or greater is desirable in an adult. • Upper lip bite test : the lower teeth are brought in front of the upper teeth. The degree to which this can be done estimates the range of motion of the tempero-mandibular joints . • Mallampati classification : examines the size of the tongue in relation to the oral cavity. The greater the tongue obstructs the view of the pharyngeal structures, the more difficult intubation

23. Cont… ■ Class I: the entire palatal arch, including the bilateral faucial pillars, are visible down to their bases. ■ Class II : the upper part of the faucial pillars and most of the uvula are visible. ■ Class III : only the soft and hard palates are visible. ■ Class IV : only the hard palate is visible. • Thyromental distance: the distance between the mentum and the superior thyroid notch. A distance greater than 3 finger breadths is desirable. • Neck circumference : a neck circumference of greater than 27 inch is suggestive of difficulties in visualization of the glottic opening.

24. Mallampati Classification of oral opening Laryngoscopic grade of Cormac & Lehane

25. Airway of Neonates and infants Relatively larger head and tongue Narrower nasal passages Anterior and cephalad larynx Relatively longer epiglottis Shorter trachea and neck More prominent adenoids and tonsils Weaker intercostal and diaphragmatic muscles Greater resistance to airflow Adult larynx is cylindrical but Childs larynx is Conical.

26. Cont….. narrowest point of the airway- cricoid cartilage (children younger than 5 years of age) glottis ( in Adult) One millimeter of mucosal edema will have a proportionately greater effect on gas flow in children because of their smaller tracheal diameters. The presence of fewer, smaller airways produces increased airway resistance.The alveoli are fully mature by late childhood(about 8 years of age). The work of breathing is increased and respiratory muscles easily fatigue.

27. Pediatric Airway

28. Anatomical change during Pregnancy. Most of the changes during pregnancy are Physiological. Capillary engorgement of the respiratory mucosa during pregnancy predisposes the upper airways to trauma, bleeding, and obstruction. Gentle laryngoscopy and smaller endotracheal tubes (6–6.5 mm) should be employed during general anesthesia.

29. EMERGENCY TRACHEOSTOMY 4 Step Horizontal skin incision Expose investing layer of Deep Fascia Divide/Displace Isthmus. Vertical incision in trachea.

30. Aspiration, pneumonia and lung abscess Right lung is most frequently involved as the right main bronchus directly takes off from principle bronchus. In the recumbent position, superior segment of the right lower lobe and posterior segment of the right upper lobe are the most dependent segment of the lung & in standing position, basilar segment of the lower lobe is most dependant. Aspiration pneumonia involving apical segments of the lower lobe is known as mendelson’s syndrome

31. Postural Drainage It consist of positioning the patient to allow gravity to assist the drainage of secretions from specific areas of the lungs Segments receiving drainage should be uppermost Treat the lower lobe segments first and upper lobe last Aerosol therapy with humidification prior to PD Worst area should be drained first On average 15-20 mins is spend in each position During PD : Chest manipulations like(Vibration, clapping/percussion, shaking )- Tappotment massage are performed in postural drainage position. Should be done in order. Vibrations and clapping first . Shaking next

32. Upper lobe-apical segments (bilateral) Half lying

33. Upper lobe-posterior segment-right left side lying 45 degree turn towards face side

34. Upper lobe-posterior segment-Left Right side lying 45 degree turn towards face side Three pillow

35. Middle lobe –lateral and medial segments right From supine 45 degree turn towards left pillow from shoulder to hip foot end raised 14”

36. Left Lingula –superior and inferior segments From supine 45 degree turn towards right pillow from shoulder to hip foot end raised 14 ” 14”

37. Lower lobe-apical segments(bilateral) Prone lying pillow under hip

38. Lower lobe-anterior basal segments(bilateral) supine lying pillow under hip foot end elevated to 18” 18”

39. Lower lobe-posterior basal segments(bilateral) prone lying pillow under hip foot end elevated 18 inches 18”

40. Lower lobe- Medial basal of right& lateral basal of left Right Side lying pillow under hip foot end elevated 18 ” 18”

41. Lower lobe-lateral basal segment-right Left side lying pillow 18”

42. Technique for airway management of a patient with suspected spinal cord injury. One individual holds the head firmly with the patient on a backboard, the cervical collar left alone if in place, ensuring that neither the head nor neck moves with direct laryngoscopy . A second person applies cricoid pressure and The third performs laryngoscopy and intubation. BUT Gold standard is FLEXIBLE FIBEROPTIC INTUBATION . laryngoscopy with in-line stabilization

43. Thank you